SANITARY NOTES ON POTABLE WATER. 
567 
aware that his experiments have been made at the instance 
of the German Imperial Board of Health. That official 
connection with a central sanitary authority induces me to 
make a few comments on Lewin’s report. 
Some two years ago an inquiry was ordered by the Im¬ 
perial Board into the merits of the spongy iron filter. The 
report was unfavorable; more I cannot say, as no details 
were given to me. Shortly afterwards, meeting one of the 
leading members of the Board, I complained that the report 
in question, had been made after those charged with it 
could not possibly have been in possession of the filters for 
more than five days. This alone naturally suffices to deprive 
it of any possible merit. It generally takes a few days before 
the filtering materials have thoroughly settled, and until 
certain chemical reactions upon which the purification by 
spongy iron depends have been thoroughly initiated. Some 
time is required to determine the result of an experiment; 
and above all one of the most important questions in con¬ 
nection with any such inquiry is how long the filtering medium 
remains efficient. Can this be decided within five davs ? 
V 
My representation led to the inquiry being transferred from 
Berlin to Munich into the hands of Lewin. I will now as 
briefly as possible explain the fate of this second attempt. 
Lewin is a believer in Dr. Pettenkofer’s theories. The 
extent to w r hich some of the latter’s followers go is shown by 
Dr. Fliigge, who has actually propounded the view T that the 
relative freedom of water from animal contamination appears 
in some way or other to be a predisposing cause of typhoid.* 
Those who hold that pure water is an essential preventive 
of certain zymotic diseases are, in his opinion, mere fc theo¬ 
rists.” Both Lewin and Fliigge look indeed upon the purity 
of water as a desideratum chiefly if not solely from an 
aesthetic point of view. You will of course understand 
that any one holding such opinions cannot attach much im¬ 
portance to the examination of water, and thus we find 
Lewin giving a report on the comparative purification of 
drinking water by animal charcoal and spongy iron without 
making one single analysis or other estimation of any kind 
whatever of a water. This curious feat can only quite be 
understood if we recollect the general state of water analysis 
in Germany. I have not met there one single chemist, with 
the exception of Dr. Hoffmann, of Berlin, who had any 
experience of the method upon which, with all its draw¬ 
backs, I look as the most satisfactory known. I allude to 
Frankland and Armstrong’s combustion process. Mr. 
# * Zeitsckrift fiir Biologie/ xiii, iv, p. 502. 
